AUGUST (AP) -- Maine health officials say vaccination opt-out rates for the state’s kindergartners increased during the 2017-2018 school year.

According to a report released this week by the Maine Center for Disease Control & Prevention, 5 percent of kindergartners were opted out by their parents this year for philosophic or religious reasons.

Health officials say low vaccination rates are responsible for outbreaks of preventable diseases. Maine has one of the highest rates of pertussis, a contagious respiratory disease, in the country.

Health officials say stricter vaccination standards will prevent future outbreaks. They point to states like California which eliminated non-medical exemptions in 2015 following a measles outbreak.